The specific goals of the proposed research are: to characterize the neutral lipid, phospholipid and glycolipid (glyceroglucolipid) components in the secretions of human salivary glands; to learn if there are quantitative and/or qualitative differences in lipids between the individuals with low and high incidence of salivary calculus, and between the individuals susceptible to caries and those resistant to caries; to determine the steps involved in biosynthesis of the glyceroglucolipids and to show the subcellular location of enzymes involved; to provide the information on the variety and concentrations of lipid deposited on the tooth surface in the process of pellicle formation, in both, caries resistant and caries susceptible individuals; to determine the lipid content and composition of the submandibular gland stones and supragingival calculus. Secretions obtained from the individual salivary gland of light calculus formers, heavy calculus formers, caries susceptible and caries resistant individuals will be used to study the content and composition of lipids. Subcellular fractionations of the major salivary glands of monkey and rat will be performed to establish the location of enzymes and the steps involved in biosynthesis of glyceroglucolipids. The lipid components of the natural and experimental pellicle (obtained by in vitro technique), supragingival calculus, and submandibular gland stones will be analyzed.